Irradiation apparatus with a rotary lock and with cams to move objects to be irradiated

ABSTRACT

The goods to be irradiated are moved by fluid actuated rams into a rotary lock and then into a chamber where the goods are moved about a radiation source by other fluid actuated rams. The goods are moved from the rotary lock in a forward manner and then displaced therefrom for movement about the radiation source. The goods are returned to the rotary lock in a reverse manner.

United States Patent Sieber [4 Aug. 22, 1972 [5 IRRADIATION APPARATUSWITH A 3,225,203 12/ 1965 Gombert ..250/108 ROTARY LOCK AND WITH CAMS To3,411,002 12/1968 Armel ..250/52 V OBJECTS TQ BE IRRADIATED 3,506,825 4/1970 Hartmann ..250/52 [72] lnventor: Adolf Sieber, Winterthur,Switzerland {73} Assignee: Sulzer Brothers, Ltd., Winterthur,

Switzerland [22] Filed: Sept. 18, 1969 [211 PP V Q-F. 5L v [30] ForeignApplication Priority Data 7 7 Sept. 20, 1968 Switzerland 1 41 41/68 Y[52] US. Cl. ..250/52, 250/106 R, 250/108 R [51] Int. Cl ..H01j 37/00[58] Field of Search...250/52, 106 R, 108 R, 108 WS [56] ReferencesCited UNITED STATES PATENTS 3,142,759 7/1964 Jefferson et al. ..250/52Primary Examiner-James W. Lawrence Assistant ExaminerC. E. ChurchAttorney-Kenyon & Kenyon Reilly Carr & Chapin [57] ABSTRACT The goods tobe irradiated are moved by fluid actuated rams into a rotary lock andthen into a chamber where the goods are moved about a radiation sourceby other fluid actuated rams. The goods are moved from the rotary lockin a forward manner and then displaced therefrom for movement about theradiation source. The goods are returned to the rotary lock in a reversemanner.

8 Clairm, 4 Drawing Figures Patented Aug. 22, 1972 3,686,502

4 Sheets-Sheet 1 In ventor: ,QPOLF 5/5552 Patented Aug. 22, 19723,686,502

4 Sheets-Sheet 2 Inventor- ADOLF $15551? BY 7 M/ Patented Aug. 22, 19724 Sheets-Sheet 5 Inventor:

ADOL F 3 IE BE F? 8V Patented Aug. 22, 1972 3,686,502

4 Sheets-Sheet 4 Inventor- ADOLF SIEBEF? BY J WTTO NEYS IRRADIATIONAPPARATUS WITH A ROTARY LOCK AND WITH CAMS TO MOVE OBJECTS TO BE IATEDThis invention relates to an irradiation apparatus. More particularly,this invention relates to an irradiation apparatus for radiatingconveyed goods in a continuous manner.

I-Ieretofore, various types of irradiation devices have been known forradiating conveyed goods. For example, devices have been constructedwith a rotatable wheel mounted eccentrically in a shielded housing witha specimen holder at one point of the wheel so as to carry a specimenfirst from the outside of the housing to the inside for radiation andthen back to the outside. Generally, these devices have only permitted asingle specimen to be subjected to a radiation treatment at any onetime. In other instances, various conveyors have been used to move aseries of goods about a radiation source. However, these conveyors haveusually required rather large and expensive housings and conveyoractuating systems.

Accordingly, it is an object of the invention to provide a simple drivesystem for moving a series of charges in a continuous manner through anirradiation zone.

lt is another object of the invention to provide a portable irradiationapparatus.

It is another object of the invention to irradiate charges in a simpleefficient economical manner.

Briefly, the invention provides an irradiation apparatus which isconstructed with a shielded irradiation chamber, a rotary lock in a wallof the chamber for receiving charges to be irradiated within a recess,means for conveying the charges in a path around a radiation sourcemounted within the chamber and means for moving the charges in astraight line between the recess of the rotary lock and the path.

In one embodiment, a device is provided in the region of the rotary lockto move the charges in a direction perpendicularly of the straight lineof movement between the recess and path so as to initiate movement aboutthe irradiation source and to return the charges to position in front ofthe recess.

In another embodiment, a device is provided in the region of the rotarylock to move the charges perpendicularly of the straight line ofmovement between the recess and path so as to initiate movement aboutthe irradiation source while another device is provided to move thecharges out of the path directly into the recess.

In still another embodiment, the means for moving the charges betweenthe recess of the rotary lock and the path about the irradiation sourceis mounted within the rotary lock and includes a reciprocally mountedtray. The tray is movable from a position within the recess to aposition within the path and vice versa so as to deliver or receive acharge.

In all of the above embodiments a transport means is also provided tomove the charges into and out of the recess of the rotary lock when therecess is facing away from the irradiation chamber. Further, thetransport means serves to move the charges into and out of the recess inthe same line as the charges are moved into and out of the irradiationpath within the irradiation chamber.

The apparatus requires only a very simple drive for the rotary lock asthe lock need only occupy two positions in order to introduce chargesinto the irradiation chamber. One of these positions will be when therecess faces away from the chamber. when an irradiated charge is removedfrom the recess and replaced by a charge to be irradiated: The rotarylock may then be rotated through until the recess faces the chamber whenthe charge to be irradiated is placed on the path around the irradiationsource and replaced in the recess by an irradiated charge.

As the rotary lock contains only one recess, the lock can be made ofsmaller diameter than would be necessary if the lock had a number ofrecesses.

Conveniently, the path of movement about the irradiation source isrectangular and the means for conveying the charges includes a device inthe region of the rotary lock and three other devices, each beingsituated at each corner of the path.

These and other objects and advantages of the invention will become moreapparent from the following detailed description and appended claimstaken in conjunction with the accompanying drawings in which:

FIG. 1 illustrates a horizontal section through one embodiment of anirradiation apparatus according to the invention;

FIG. 2 illustrates a horizontal section through another embodiment of anirradiation apparatus according to the invention;

FIG. 3 illustrates a horizontal section through a third embodiment of anirradiation apparatus according to the invention; and

FIG. 4 illustrates a view taken on line A-B of FIG. 3.

Referring to FIG. 1, the irradiation apparatus has a block 1 ofshielding material, for example, concrete, which encloses an irradiationchamber 2 containing a source of gamma radiation, for example Cobalt 60,which is in the form of a plate 3. The material to be irradiated ismoved in the form of charges 4 in two rows, one on each side of theradiation source 3, over a sliding surface which forms the floor of thechamber 2; each charge follows a rectangular path. At each of the fourcorners of the path is a ran 5a to 5d of a conveying means which ismounted in the block 1 and partly enclosed in lead by means of which thecharges 4 are moved around the rectangular path. For reasons of space,the ram 5d is situated below the "floor of the chamber 2 and a plate 6is mounted on its piston rod which projects into the irradiation chamberthrough a slot 7 in the floor.

A rotary lock 10 is situated in the wall of the shielding block 1adjacent one of the short sides of the irradiation chamber 2. This lock10 consists basically of a circular plate having an upstanding annularwall 11, e.g., of lead, mounted thereon. The wall 11 is provided with agap at one part which extends over the entire height of the wall to forman opening 12 through which a charge 4 can be introduced into or removedfrom the recess so formed in the lock 10.

In order to move a charge out of the rotary lock 10, a transfer devicein the form of a ram 13 is mounted in the recess of the lock 10 and isconnected to a suitable actuating means (not shown) which actuates thepiston of the ram 13 to move the charges forwardly out of the lock 10.Further, in order to rotate the rotary lock 10 between a position inwhich the recess faces outwardly of the chamber 2 and a position (asshown) in which the recess faces into the chamber 2, which positions arein alignment with each other, i.e., 180 apart, a toothed sector 79 ismounted below the circular plate of the lock 10 and is fixedly connectedto the lock 10. The sector 79 meshes with a correspondingly tooth rack80 which forms an extension of a reciprocal piston rod 81 of aservo-motor 82 so as to be oscillated upon reciprocation of the rack 80by the servo-motor 82. The rotary lock 10 is thus driven through 180.

In order to move a charge 4 into the rotary lock 10 from within thechamber 2, a transfer device in the form of a ram 14 is mounted betweentwo rows of charges 4 in the chamber 2 opposite the ram in the rotarylock 10. This ram 14 is actuated by a suitable means (not shown) toreturn an irradiated charge 4 into the recess of the rotary lock. Inaddition, a ram transfer device in the form of a 15, situated outsidethe shielding block 1 and opposite the ram 13, serves to move a charge 4into the rotary lock 10 from outside the shielding block 1. The rams 13to 15 are arranged in substantially the same vertical plane.

A transport means is disposed outside the wall of the shielding block 1for moving the charges 4 to and from the rotary lock 10 when the lock 10is positioned with the recess facing outwardly of the chamber 2. Thistransport means includes a supply conveyor 16 to the right of the ram 15as viewed on which the charges 4 to be irradiated are supplied and aroller conveyor 18 to the opposite side of the ram 15 on whichirradiated charges are removed.

It is noted that each of the rams 5a to 5d, 13, 14, 15 and 17 consistsof a piston and cylinder and is operated by a pressure fluid, e.g., air,as is known. The feed lines for the pressure fluid and the controlmechanism are omitted from the drawings for the sake of clarity.

The apparatus operates as follows: The charges which are to beirradiated move one after the other along the supply conveyor 16 untilthey are in front of the ram 17, which displaces one charge at a time tothe left as seen in FIG. I. The rotary lock is rotated at the same timeto a position 180 from the position shown in FIG. 1, so that the opening12 faces the ram 15. The charge is then pushed by the ram into the lock10, which is then rotated by the servo-motor 82 into the position shown.Next, the ram 13 pushes the charge 4 out of the lock 10 into theposition indicated by chain-lines in the irradiation chamber 2 in thepath of movement about the radiation source 3. The ram 5a then displacesthe charge perpendicularly to the right as viewed until the charge isabove the groove 7. During the next stage, the ram 5b moves theleft-hand row of charges one charge width so as to make room for acharge in front of the ram 5b. The ram 50 then moves a charge from theright-hand row into the left-hand row. The ram 5d then moves theright-hand row of charges one charge width. Thereafter, the ram 5a movesthe charge immediately in front of it into the position shown bychain-lines. This charge which has been irradiated is pushed by the ram14 into the rotary lock 10, which is then rotated by means of theservo-motor 82 so that the opening 12 faces the ram 15. The irradiatedcharge is then pushed out of the lock 10 by the ram 13, and the ram 17moves this charge onto the roller conveyor 18, on which it rolls away,and then brings a new charge in front of the opening 12.

It is noted that the various motions of the respective rams andservo-motor are synchronized in any suitable known manner so as toeffectuate the above operation. As such a synchronism is well known,such is not further described.

Referring to FIG. 2, wherein like reference characters refer to likeparts as described above, the shielding block 1 is provided with anelongated irradiation chamber 2 which is disposed perpendicularly of thetransport means for supplying and removing the charges 4. Further, rams5a to 5d are provided adjacent the comers of the irradiation chamber 2,and the rotary lock 10 is situated at one comer in such a way that theram 5d at the adjacent comer also serves to introduce the charges 4 intothe lock 10'. This arrangement has the advantage that the ram 14provided in the embodiment shown in FIG. 1 can be omitted. Also, thereis no ram underneath the floor of the chamber 2, and the minimumdistance between the two rows of charges is not determined by the widthof the ram 14. The rotary lock 10 whose basic construction is the sameas that of the rotary lock 10, is smaller in diameter than the latter.In fact, the diameter of the lock 10 is less than the wall thickness ofthe shielding block 1 at this point. This reduction is possible becausethe ram 13' inside the lock is different in construction from the ram 13inside the lock 10. The length of the casing of the ram 13' is shorterthan the stroke of its piston, for example, due to a conventionaltelescopic construction of the piston.

In operation, a charge 4 which is to be irradiated is introduced intothe lock 10' and then into the position as shown in the same manner ashas been described with reference to FIG. 1. In the next stage, the ram13 pushes the charge out of the lock 10' to a position in front of theram 5a. The ram 5b then pushes a charge of the left-hand row which is infront of it in front of the ram SC on the right-hand side. The ram 50now pushes the left-hand row forwardly a half or a whole charge width.The irradiated charge pushed into the lock by the ram 5d is then (afterthe lock 10 has rotated through transferred onto the roller conveyor 18by means of the rams 13 and 17 as already described with reference toFIG. 1.

Apart from the advantages mentioned above, the apparatus shown in FIG. 2has the further advantage that the irradiation chamber 2 is smaller andthe weight of the shielding block 1 is therefore reduced.

Referring to FIGS. 3 and 4, the irradiation apparatus has a rotary lock10" containing a tray 20 which slides in two grooves 21 havingtriangular cross-sections. The end of the tray 20 which is on the rightin FIG. 4 carries two upwardly projecting lugs 22, each of which has aslot in which a pivot 24 is slidably mounted. Each pivot 24 is mountedon a two-armed lever 25 which is mounted on a pin 26 carried in theannular wall of the rotary lock. The upper ends of the two two-armedlevers 25 are connected by a crosspiece 27 which has a knob 28 in themiddle. This knob 28 projects into a U- shaped guide 29 which is open atthe bottom and at both ends and is attached to the end of a piston rod30 of a ram 31. As the piston of the ram 31 moves to the right in FIG.4, each lever 25 pivots about the pin 26 to cause the sliding tray 20 tobe displaced to the left along the grooves 21 out of the lock and ontoto move the irradiated charge onto the roller conveyor 1 18, on which itrolls away, while at the same time a new and forwards, a straight groove35 which opens downwardly is provided in the shielding block 1. Bothends of this groove 35 lead into an annular groove 36, again opendownwardly, which has a rectangular crosssection and is arranged to beconcentric with the rotational axis of the rotary lock 10'. With thesliding tray in-the position shown by solid lines, the lock 10 can beturned while, the knob 28 (projecting sideways fromthe guide 29) movesin the annular groove 36. This annular groove 36 therefore serves toguide the sliding tray 20 so that no relative motion occurs betweenthesliding tray 20 and rotary lock 10" when the lock rotates.

Grooves 38 having triangular cross-sections and corresponding to thegrooves 33 inside the irradiation chamber 2 are provided on the outsideof the shielding block 1 so that the sliding tray 20 can still beextended when the lock 10" has turned through 180. The lock 10" rests ona ball thrust bearing 39 and is set into the floor of the shieldingblock 1, to prevent gamma radiation from escaping under the end of thelock. For the same reason, a shoulder 40 is provided at the upper end ofthe rotary lock which projects into the shielding block.

The apparatus shown in FIGS. 3 and 4 operates as follows. In order tointroduce a charge for irradiation, the rotary lock 10" is brought outof the position shown into a position rotated through 180. At the sametime,the piston of the ram 31 is moved to the right, the latterbeginning movement somewhat later than and ending somewhat earlier thanthe rotary lock 10". As a result, the knob 28 can leave the guide 29 atthe point shown and then re-enter the guide 29 when the guide 29 hasmoved to its right-hand position. It is therefore unnecessary for theram 31 to be constructed so as to have an intermediate position betweenits two end positions. The piston of the ram 31 is then moved to theleft, and the sliding tray 20 comes out of the lock 10" along thegrooves 38. A charge for irradiation is pushed by the ram 17 onto thesliding tray 20, which is then withdrawn into the lock 10 by means ofthe ram 31. Next, the lock is turned through 180, the piston of the ram31 again starting later and arriving earlier in' its left-hand position,so that the position shown by solid lines in FIG. 4 is reached. By meansof the ram.3l, whose piston moves to the right, the tray 20 runs ontothe grooves '33, whereupon the ram 5a displaces the charge to beirradiated to the right as viewed in FIG. 3 so that it joins theright-hand row of charges. The ram 5b then moves the left-hand rowforward one charge width to bring an irradiated charge onto the tray 20.While the ram 5c and then the ram 5d are fulfilling their functions, theram 31 withdraws the tray 20 into the rotary lock 10", so that theposition shown by solid lines is reached again. Next, the lock 10" turnsthrough charge is pushed onto the tray 20 in order to be irradiated.

In the apparatus shown in FIG. 3 and 4, there is a further reduction inthe diameter of the rotary lock and in the number of rams, the rams 13and 13' being omitted. The movement of the sliding tray 20 by means ofthe ram 31, like movement of the lock by means of the servo-motor 82,has the advantage that, because the piston occupies limit positions, thesliding tray is alwhile the piston of the ram 31 moves to the right.

When this piston next moves to the left, the tray 20 is moved along thegrooves 38 and the ram 17 is operated ways certain to reach itswithdrawn and extended positions.

The apparatus have been described as being of permanent construction;however, the apparatus can also be constructed in a portable or movablemanner. In such a case, the shielding block might be of lead instead ofconcrete. Also, the shielding block might be built of separate,prefabricated elements light enough to be transported. By this means, anapparatus can be built which could be disassembled when required andreerected on another site. It is also possible for each charge 4 to becomposed of several smaller charges.

What is claimed is:

1. An irradiation apparatus comprising a wall defining a shieldedirradiation chamber for housing a radiation source therein at aradiation source station;

means for conveying charges to be irradiated in a path around saidradiation source station within said chamber, said path including atleast two straight line segments;

a rotary lock in said shield wall having a recess for receiving chargesto be irradiated, said rotary lock having a single position in whichsaid recess faces outwardly of said chamber to receive and unload acharge and a single position in which said recess faces inwardly of saidchamber, to receive and unload a charge;

means for loading and unloading to and from said recess, said meansincluding at least two transfer devices situated in substantially thesame plane for moving the charges in a straight line; and

a device in the region of said rotary lock for moving charges withinsaid chamber in a direction perpendicular to said straight line betweensaid straight line and said path around said radiation source station.

2. An irradiation apparatus as set forth in claim 1 in which said pathis rectangular and said means for conveying the charges includes saiddevice and three other devices, each device being situated at arespective corner of said path.

3. An irradiation apparatus as set forth in claim 2 in which said rotarylock is situated at one corner of said path so that said device at anadjacent comer is arranged to load said rotary lock when said recessfaces said irradiation chamber.

4. An irradiation apparatus as set forth in claim 1 further including acharge-receiving member connected to one of said transfer devices to bemoved radially into and out of said rotary lock.

5. An irradiation apparatus as set forth in claim 4 wherein said onetransfer device includes a piston rod movable in a fixed cylinder, saidpiston rod being arlock upon reciprocation of said rack.

7. Apparatus as set forth in claim 1 in which said means for moving thecharges in a straight line comprise fluid-actuated rams.

8. Apparatus as set forth in claim 1 in which said device in the regionof said rotary lock is a fluid-actuated ram.

UNITED- STATES PATENT OFFICE CERTIFICATEOF CORRECTIN Patent No.3,686,502 Dated August 22, 1972 Adolf Sieber Inventor(s) It is certifiedthat error appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Column 2, line #5, "ran" should be --.ram-- Column 3, lines 19 and 20,"ram transfer device in the form of a 15'' should be --tra.nsfer devicein the form of a. ram l5--.

Signed and sealed this 9th day of January 1973'.

(SEAL) Attest:

EDWARD M.FLETGHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents FORM PO-10 0 USCOMM-DC 60376-P69 U.S GOVERNMENT PRINTINGOFFICE: I969 0-365-334

1. An irradiation apparatus comprising a wall defining a shieldedirradiation chamber for housing a radiation source therein at aradiation source station; means for conveying charges to be irradiatedin a path around said radiation source station within said chamber, saidpath including at least two straight line segments; a rotary lock insaid shield wall having a recess for receiving charges to be irradiated,said rotary lock having a single position in which said recess facesoutwardly of said chamber to receive and unload a charge and a singleposition in which said recess faces inwardly of said chamber, to receiveand unload a charge; means for loading and unloading to and from saidrecess, said means including at least two transfer devices situatEd insubstantially the same plane for moving the charges in a straight line;and a device in the region of said rotary lock for moving charges withinsaid chamber in a direction perpendicular to said straight line betweensaid straight line and said path around said radiation source station.2. An irradiation apparatus as set forth in claim 1 in which said pathis rectangular and said means for conveying the charges includes saiddevice and three other devices, each device being situated at arespective corner of said path.
 3. An irradiation apparatus as set forthin claim 2 in which said rotary lock is situated at one corner of saidpath so that said device at an adjacent corner is arranged to load saidrotary lock when said recess faces said irradiation chamber.
 4. Anirradiation apparatus as set forth in claim 1 further including acharge-receiving member connected to one of said transfer devices to bemoved radially into and out of said rotary lock.
 5. An irradiationapparatus as set forth in claim 4 wherein said one transfer deviceincludes a piston rod movable in a fixed cylinder, said piston rod beingarranged to be coupled to said member when said member is moved out ofsaid rotary lock and to be disconnected from said member when saidmember is in said rotary lock and said rotary lock rotates.
 6. Anirradiation apparatus as set forth in claim 1 further including afluid-actuated ram connected to a rack, and a toothed element attachedto and between said rack and said rotary lock for rotating the rotarylock upon reciprocation of said rack.
 7. Apparatus as set forth in claim1 in which said means for moving the charges in a straight line comprisefluid-actuated rams.
 8. Apparatus as set forth in claim 1 in which saiddevice in the region of said rotary lock is a fluid-actuated ram.